HP- 45 calculator shown in
Figure 3), I used two
MAX7219 ICs to make a
colorful 10-digit numeric
display by just wire-wrapping each LED
segment to the MAX7219
driver output using the
schematic. From this, you
can see how I wire-wrapped the digits and
connected them using
.100 pin headers and
white prototyping
breadboards — all
powered by a single nine
volt battery. Be aware that
large LEDs require more
power and may not
display as brightly unless
some adjustments are
made to the brightness
command. (I am currently
working on a DIY VEX
electric train set which I
plan to outfit with
separate white LEDs so
that I can use the MAX7219 to add
lighting to the passenger cabin and the
main engine so that it looks cool when it
runs at night.)

PIC18 C Numeric LED Display Application

A more detailed schematic (Eagle) is
provided in the download package on the

SERVO website as Figure 1. sch.

FIGURE 1. For this experiment, I used a MAX7219 numeric LED display driver
to manipulate five numeric LED displays as shown in this schematic.